With Saracens lock Hayden Smith about to trade rugby union for the NFL with the New York Jets, we take a look at some other notable players with more than one string to their bow in Scrum Sevens.

Sonny Bill WilliamsNot content with bringing the offloading of rugby league to union, Williams has taken to the boxing ring on a number of occasions and is currently the New Zealand heavyweight champion after a first-round knockout of Clarence Tillman III earlier in 2012. A Rugby World Cup-winner with the All Blacks, Sonny Bill's boxing career has spanned six fights and while his opponents have at times looked more comfortable waiting for a bus than trading punches, he retains an unbeaten record.

Jeff WilsonWilson made his first mark in international sport with the New Zealand One Day International cricket side in 1992-93. His promise in cricket did not match his rugby acumen though and after electing to pursue an All Black career he became a legend. He played 60 Tests for New Zealand between 1993 and 2001, scoring 44 tries to lead their all-time chart for a time before Doug Howlett took over at the summit. His retirement from rugby in 2001 came as he went in search of a Test cap in cricket and while he again forced his way into the Black Caps' limited overs teams in 2005, he could not make the final step.

JPR WilliamsOne of the game's most celebrated players, Williams played 55 Tests for Wales and eight for the Lions on their victorious tours of 1971 and 1974 at fullback. In his youth he had been a promising tennis player, winning a British Junior title at Wimbledon against future British No.1 David Lloyd in 1966. With his third love, medicine, outweighing both sports in his affection, a life as a professional tennis player was not an option, paving the way for his rugby success and also his career as an orthopaedic surgeon. "I would have chosen tennis before rugby," he said in an interview with the Observer in 2008 when asked to choose between a pro career in either sport. "I'd have done so because tennis is much more lucrative now and much more enticing - and because of the dangers of rugby. It's much more physical than when I played."

Dan LyleLyle's ascent to the top of English rugby was a bolt from the blue. A former Washington Redskins trialist in the NFL, Lyle took up rugby to keep fit and soon made the switch from Old Mission Beach Athletic Club to Bath in 1996. A brilliant No.8, his decision to turn down a further offer from the Minnesota Vikings was very much rugby's gain. He won the Heineken Cup in 1998 and retired following the 2003 Rugby World Cup, having won 45 caps for the USA. "He combines the skills developed in common American sports - football, basketball and soccer - with a blessed disregard for English stuffiness," wrote Sports Illustrated.

Matt StevensAfter copping a two-year drugs ban, Stevens turned to martial arts to rediscover a competitive edge. A student of Brazilian Jiu-jitsu, the England prop spent his downtime after leaving Bath competing, rising to the level of British intermediate champion. He fought - without a great deal of success - at the World Championships before re-emerging as a rugby player with Saracens, winning the Premiership and a spot in the England squad in time for the Rugby World Cup in 2011. "After my first jiu-jitsu fight I thought: 'I love this feeling, I love that competitive edge. I've got to get back to doing what I'm good at,'" he told The Guardian.

Tuppy Owen-SmithIn 1929 Owen-Smith made his mark in England with a cricket bat, smashing 129 for South Africa in a Test match at Headingley. Also a champion lightweight boxer, his rugby career took off when he returned to England in 1930 on a Rhodes Scholarship to study medicine at Oxford. He won Blues in cricket and rugby before making his Test debut for England in 1934 against Wales in Cardiff. An attacking fullback, he played 10 Tests in all and also captained England in their three Home Nations matches in 1937 for a clean-sweep.

Eric 'Snowy' TindillTindill was the only man to represent New Zealand in Test cricket and rugby, also officiating both games at the highest level. A wicket-keeper in cricket, he was a versatile rugby player who could alternate between scrum-half and fly-half. After winning selection for the All Blacks' 1935-36 tour to the northern hemisphere he struggled to make an impact due to the form of Otago first-five Jack Griffiths. A strong showing against London Counties, in which he slotted two drop-goals, secured his Test bow against England. There the All Blacks were swatted aside 13-0 as England's Russian Prince Alex Obolensky made one of the most famous debuts of all time. Tindill's first Test proved to be his last as he was selected for the cricket team in 1937, ending his chances of touring with the All Blacks.